This clinical experiment will examine the effectiveness of a cognitive-behavioral group treatment model emphasizing the prevention of relapse in gay and bisexual males who are at risk of AIDS because of ongoing unsafe sexual activity. The subjects will be 240 adults who will have engaged in at least one high risk sexual behavior in the 90 days prior to baseline assessment, will have expressed concern about not being able to avoid such behavior, will not have indicated currently being psychologically or physically dependent on alcohol or other psychoactive drugs, will not have been diagnosed as having AIDS, and will have agreed to both the random assignment and treatment in a group context. Two recruitment periods are planned, each of which is intended to result in the enrollment of 120 subjects, 60 of whom will receive immediate treatment and 60 of whom will serve as the no- treatment control group. The latter individuals will subsequently receive treatment beginning at the point at which those receiving immediate treatment receive their one month post-treatment follow-up assessment. Treatment will consist of 16 weekly two- hour group sessions, followed by three additional sessions devoted to both treatment and assessment. The latter will occur at one month intervals. The general questions guiding this study are: (1) Can psychotherapy programs for changing high risk sexual behavior be designed and marketed so that even relatively closeted men can and will participate? (2) How effective is a cognitive-behavioral approach for helping gay and bisexual men achieve and maintain changes in their sexual practices and sexual expression to reduce risk of HIV transmission? (3) Is treatment success related to subject characteristics? If so, how? (4) Will the therapy approach lead to improved scores on measures of social integration vs. isolation, and subjectively felt satisfaction with sexual expression?